help with the dashboard time calculation needed

[damucka]

Hello,

I have relatively easy issue I am struggling with.
I would like to calculate the time difference in seconds between the form.to and form.from set from the time picker. The dashboard beginning looks as follows:

<form>
  <label>System KPI Dashboard Clone</label>
  <fieldset submitButton="false" autoRun="true">
    <input type="dropdown" token="sysid" searchWhenChanged="true">
      <label>System</label>
      <fieldForLabel>SYSYSID</fieldForLabel>
      <fieldForValue>SYSYSID</fieldForValue>
      <search>
        <query>| dbxquery query="select distinct sysysid from sapiop.zkpic_sysreltask where hana = 'X' order by sysysid" connection="HANA_MLBSO"</query>
        <earliest>-24h@h</earliest>
        <latest>now</latest>
      </search>
      <default>ISP</default>
    </input>
    <input type="time" token="field1" searchWhenChanged="true">
      <label>Time</label>
      <default>
        <earliest>-24h@h</earliest>
        <latest>now</latest>
      </default>
      <change>
        <eval token="form.from">strftime(relative_time(now(),'earliest'), "%F %T")</eval>
        <eval token="form.to">strftime(relative_time(now(),'latest'), "%F %T")</eval>
        <eval token="timediff">$form.to$ - "$form.from$</eval>
      </change>
    </input>
  </fieldset>
  <row>
    <panel depends="$hidden$">

However the timediff does not get set.
I tried different combinations with relative_time, etc. but is seems not to get set.
How would I do it?

Kind regards,
Kamil

[richgalloway · Accepted solution]

$form.to$ and $form.from$ are strings and you can't subtract strings. Use the integer form of each time, instead.

<eval token="timediff">relative_time(now(), 'latest') - relative_time(now(), 'earliest')</eval>

[damucka]

I solved the issue, was actually not that difficult ...

<eval token="form.from">strftime(relative_time(now(),'earliest'), "%Y-%m-%d %H:%M:%S")</eval>
<eval token="form.to">strftime(relative_time(now(),'latest'), "%Y-%m-%d %H:%M:%S")</eval>
<eval token="timediff">strptime($form.to$, "%Y-%m-%d %H:%M:%S")  - strptime($form.from$, "%Y-%m-%d %H:%M:%S")</eval>